光度分析显色试剂的量子化学研究——Ⅰ.变色酸双偶氮膦类分子的电子光谱与π轨道能级

变色酸双偶氮膦类显色剂,是国内近年来迅速发展的一类希土光度分析试剂,关于这类试剂的合成及应用,已做了许多工作,并取得不少成果。在此基础上,为改进或研制新的光度分析试剂,掌握显色试剂结构与性能的规律性关系,已成为势在必行的事;而在这些研究中,量子化学方法又是一种相当重要的手段。因为凭借量子化学基本原理及概念,按所选定的某些简化模型,借助经验参数作近似计算,可获得试剂传统研究方法难以得到的一些重     

有机试剂的结构与性质的关系的研究

前言有机试剂是用于化学元素和化合物的测定、分离与浓集、掩蔽的有机化合物。这类化合物数量很多,在分析化学中得到极其广泛的应用。有机试剂结构及其与反应性能之间关系的研究是有机试剂理论研究的基本问题。早在本世纪二十年代Feigl就提出了分析功能团的概念。这个概念广泛地应用于有机试剂的研究中,并不断得到丰富和发展。这一概念的出现,为人们研究有机试剂结构与反应性能的关系奠定了基础。随着现代科学技术的不断发展,X射线衍射、红外光谱、拉曼光谱等现代技术也相继用于有机试剂的研究,使人们对有机试剂的认识进一步加深。此外近代迅速发展起来的络合物结构理论、量子化学方法以及计算技术也被用于有机试剂的研究中,从而使得从理论上     

变色酸双偶氮胂酸型试剂与稀土元素的显色反应

本文综述了作者近年来对变色酸双偶氮胂酸型试剂的研究工作,包括显色反应的灵敏度、选择性、类型、机理、多元络合物的形成反应,及其在分析中的应用。用量子化学和反应动力学法研究了这类试剂在速差动力分析法中应用的可能性,对已用于光度分析的新变色酸双偶氮胂酸型试剂进行了概括。     

多氯取代对二苯并呋喃结构和电荷分布影响的量子化学研究

多氯取代对二苯并呋喃结构和电荷分布影响的量子化学研究苏忠民，盛连喜，赵宝忠（东北师范大学化学系，长春１３００２４）王东仁，李金昶（东北师范大学测试中心，长春，１３００２４）关键词：多氯代二苯并呋喃，电荷分布，量子化学计算本文采用量子化学方法，以多氯二...     

7-(2-吡啶偶氮)-8-羟基喹啉溶液平衡的研究

本文应用分光光度法及量子化学方法,研究了7-(2-吡啶偶氮)-8-羟基喹啉在溶液中的酸碱平衡及其存在形式。测定了在有无表面活性剂存在下,试剂的离解常数。互变异构平衡的研究指出,加入有机溶剂使异构平衡向偶氮型方面移动,在表面活性剂存在下,平衡向醌型方面移动。     

量子化学方法在锂离子电池电解液研究中的应用

总结了近年来量子化学方法在锂离子电池电解液研究中的应用进展,阐述了量子化学方法在新型锂盐设计、功能添加剂作用机理分析和电极/电解液界面膜的形成过程研究中发挥的作用,对其用来设计锂离子电池电解液功能分子作出展望。     

壳聚糖膜的量子化学计算

采用Gaussian92程序，用AM1半经验量子化学方法优化壳聚糖膜模型的分子结构，在此基础上用量子化学从头算STO-3G方法计算，研究了壳聚糖-戊二醛的阳离子膜和阴离子膜的几何构型、能量、键序和电子迁移，讨论了膜形成的成键形式和膜的结构及稳定性     

分子磁性的量子化学研究进展

本文概述了研究分子磁性的量子化学方法和研究进展。首先介绍分子磁性研究中的量子化学原理和所使用计算方法,总结了有代表性的自由基、自由基-金属配合物、桥联多核过渡金属配合物等分子磁性的研究情况,并对今后研究分子磁性的量子化学方法作了展望。     

不同硬件环境下量子化学软件的测试比较

计算机技术的飞速发展使得量子化学计算方法、水平和运算速度等方面有了很大的提高,同时也不断推出新的量子化学软件,诸多软件中,Gaussian和Gamess-US一直处于领先地位,是量子化学工作者的主要研究工具,研究这两种软件的计算速度具有比较强的代表性.针对国内使用微机进行量子化学研究有一定普遍性,我们以单分子计算和过渡态计算为例,对不同硬件产品作了大量测试工作,目的在于给广大的量子化学工作者购机时提供一些参考.     

基于量子化学计算方法的天然气水合物稳定性研究进展

天然气水合物以资源丰富、优质、洁净等特点,被视为21世纪新能源。天然气水合物稳定性的研究对天然气水合物资源勘探开发具有重要意义。本文简述了微观、介观、宏观、矿藏四个尺度天然气水合物稳定性的研究,重点从微观量子尺度介绍了量子化学计算方法对水合物晶体结构及其稳定性以及水合物宏观物理特性微观表征的计算研究。应用量子化学计算方法可以对天然气水合物的晶体结构、电子轨道分布、振动光谱、成键特性及主客体相互作用进行计算研究,其结果能够为天然气水合物在油气储运、水合物成藏、开采及其综合利用等方面的研究提供理论支持。目前,量子化学计算方法的优化与分子动力学模拟、分子力学模拟等方法的结合将有助于水合物形成和分解微观机理研究的发展,提升计算精度和扩大研究体系,为矿场尺度的天然气水合物资源开采利用提供理论支持。     

Estimation of the main characteristics of reagents of the diphenylamine series using quantum chemistry and chemometrical methods

The possibility of using quantum chemistry and chemometrical methods for the a priori estimation of the major analytical characteristics of analytical reagents has been demonstrated by the example of compounds of the diphenylamine series. The employed methods for the estimation of the characteristics of compounds are simple and rapid and are equal to the known experimental approaches in terms of precision.     

Ferrocene-based derivatization in analytical chemistry

Ferrocene-based derivatization has raised considerable interest in many fields of analytical chemistry. This is due to the well-established chemistry of ferrocenes, which allows rapid and easy access to a large number of reagents and derivatives. Furthermore, the electrochemical properties of ferrocenes are attractive with respect to their detection. This paper summarizes the available reagents, the reaction conditions and the different approaches for detection. While electrochemical detection is still most widely used to detect ferrocene derivatives, e.g., in the field of DNA analysis, the emerging combination of analytical separation methods with electrochemistry, mass spectrometry and atomic spectroscopy allows ferrocenes to be applied more universally and in novel applications where strongly improved selectivity and limits of detection are required.     

Cluster compounds help to bridge the gap between atom and solid

We discuss in this paper the possibilities to calculate electronic structure of the metal atom cluster compounds (CC) and present some interesting results from binuclear and hexanuclear cluster prototypes. The aim of this work is to show that quantum chemistry of CC has an extraordinary potential to provide:(1) interesting examples of the highly dispersed metallic state (only quantum chemistry has developed a model to bridge the whole gap between atom and solid, the analytic cluster model),(2) simple models of local bulk situations (e.g. behaviour of impurity atoms), developing cluster-bulk analogy,(3) simple models of local surface phenomena (e.g. chemisorption processes), developing cluster-surface analogy. The most important point is to initiate knowledge transfer between complex chemistry, surface chemistry, field of highly dispersed metals and metal physics.     

Application of quantum dots as analytical tools in automated chemical analysis: A review

Colloidal semiconductor nanocrystals or quantum dots (QDs) are one of the most relevant developments in the fast-growing world of nanotechnology. Initially proposed as luminescent biological labels, they are finding new important fields of application in analytical chemistry, where their photoluminescent properties have been exploited in environmental monitoring, pharmaceutical and clinical analysis and food quality control. Despite the enormous variety of applications that have been developed, the automation of QDs-based analytical methodologies by resorting to automation tools such as continuous flow analysis and related techniques, which would allow to take advantage of particular features of the nanocrystals such as the versatile surface chemistry and ligand binding ability, the aptitude to generate reactive species, the possibility of encapsulation in different materials while retaining native luminescence providing the means for the implementation of renewable chemosensors or even the utilisation of more drastic and even stability impairing reaction conditions, is hitherto very limited. In this review, we provide insights into the analytical potential of quantum dots focusing on prospects of their utilisation in automated flow-based and flow-related approaches and the future outlook of QDs applications in chemical analysis.     

Methods for the calculation of spherically averaged Compton profiles with GTOs

For the first time, an analytical and efficient algorithm for the evaluation of spherically averaged reciprocal form factors B(s)=〈B( s )〉_Ω using Gauss-type basis functions is presented. The spherically averaged Compton profile is available by Fourier transformation of the reciprocal form factor. The algorithm has been successfully implemented in connection with the quantum chemistry codes GAMESS and CRYSTAL92, which perform Hartree–Fock calculations for molecules and solids. In addition, an analytical algorithm for the direct evaluation of spherically averaged Compton profiles and the moments 〈p^ν〉 (ν≥−1) via the momentum density is proposed for Gauss-type basis functions. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 65 : 213–223, 1997     

Hypervalent‐Iodine(III)‐Mediated Oxidative Methodology for the Synthesis of Fused Triazoles

The organic chemistry of hypervalent organoiodine compounds has been an area of unprecedented development. This surge in interest in the use of hypervalent iodine compounds has mainly been owing to their highly selective oxidizing properties, environmentally benign character and commercial availability. Hypervalent iodine reagents have also been used as an alternative to toxic heavy metals, owing to their low toxicity and ease of handling. Hypervalent organoiodine(III) reagents are versatile oxidants that have been successfully employed to extend the scope of selective oxidative transformations of complex organic molecules in synthetic chemistry. This Focus Review concerns the tandem in situ generation and 1,5‐electrocyclization of N‐heteroaryl nitrilimines into fused triazoles. We describe the importance of recently developed hypervalent‐organoiodine(III)‐catalyzed oxidative cyclization reactions, building towards the conclusion that hypervalent iodine chemistry is a promising frontier for oxidative cyclization, in particular of hydrazones, for the synthesis of fused triazoles.     

Analytical applications of co-ordination compounds

The uses of metal complex compounds in the various fields of analytical chemistry are reviewed with particular reference to newer reagents and fresh applications of established reagents. The topics covered include precipitants, volumetric reagents, indicators and solvent extraction reagents. A new method for the gravimetric determination of gold with trans-dichlorobis(ethylenediamine) cobalt(III) chloride is included.     

Green analytical chemistry: Opportunities for pharmaceutical quality control

This review article summarizes the opportunities for utilizing the green analytical chemistry (GAC) techniques and principles in the field of quality control (QC) of pharmaceuticals. Green analytical chemistry is considered a branch of the green chemistry based on the principles overlapping with the goals of sustainable development. General definitions of quality and quality control, the principles of GAC, proposals for greener sample pretreatment and greener chromatographic method of analysis applied in QC laboratories are discussed herein. The main goal is to achieve more eco-friendly analysis in QC laboratories through different strategies and techniques, replace toxic reagents, and modify or replace analytical methods and/or techniques with safer ones, making it possible to dramatically reduce the amounts of reagents consumed and waste generated.     

5-azo derivatives of rhodanine and its analogues in the analytical chemistry of the noble metals

Progress in the synthesis and theoretical study of the 5-azo derivatives of rhodanine, thiorhodanine, 3-aminorhodanine, thiohydantoin, pseudothiohydantoin, thiopropiorhodanine, and selenoisorhodanine is discussed. Emphasis is placed on peculiarities in the interaction of this series of reagents with noble metals and their practical application in analytical chemistry.     

3,4,5-Trihydroxyfluorones as analytical reagents

Acid-base, spectrophotometric, and chromaticity characteristics of 3,4,5-trihydroxy-9-(2′-sulfophenyl)-6-isoxanthone (Pyrogallol Red, PR) and its 2,7-dibromo derivative (Dibromopyrogallol Red, BPR) were considered. The effect of the ionic strength, solvents, and surfactants on these characteristics was discussed. The complexation of the reagents with metal ions in the presence of second and third components (surfactants of different natures and organic reagents) was considered. The analytical characteristics of two-, three-, and four-component complexes were compared. The selectivity of the reagents, methods for changing the selectivity, and applications in analytical chemistry were considered. It was noted that chromaticity measurements are promising for studying the complexation of ions and their determination.